Lawson and Testament families

I am looking for info on Testament (or Testerman) children raised by a Lawson family. This would have happened prior to 1915 in either Virginia or Tennessee. We are told that the mother Testament died, the father could not care for the children, so they were given to a Lawson family. Supposedly, the children took the Lawson name from that point. I have no specific dates or first names....any info will be appreciated!